550 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [26] 



important question. The young fry has been observed by nearly all 

 fishermen, but although there were great complaints that the number 

 of flounders was decreasing, no one had thought to observe whether 

 the young fry was more numerous in one year than in another, and still 

 the fisheries of the coining years depend entirely on the young fry. 



What can the authorities do in view of such a condition of affairs? 

 As nothing is known with absolute certainty, no sure steps can be 

 taken, and nothing remains but to let things go on until the complaining 

 fishermen show that they are well enough acquainted with the matters 

 about which they complain to prove the correctness of their assertions. 



From this example from recent times it will be seen that a knowledge 

 of how to take care of the fish during the spawning season is important 

 to the fishermen in more than one respect. It may be said that there 

 will scarcely be a single case where fishermen have raised complaints 

 in which a knowledge of the spawning places and of the young fry would 

 not be of vast importance. Even if in an exceptional case the knowl- 

 edge of the spawning of fish were of no importance, the statements of 

 those fishermen would deserve and receive the greatest attention who 

 could give reliable information regarding the spawning places within 

 their fishing area and regarding the life and habits of the young fry. 



The following pages are intended to aid the fishermen in gaining the nec- 

 essary knoicledge. Scientific investigation has so far only extended to 

 the history of the development of a few species of fish, but it may be 

 said that as to general principles all fish will more or less resemble each 

 other in this respect, whilst, of course, they will greatly differ as to 

 the details, which are comparatively little known. We know that in 

 laying their eggs the fish empty their sexual organs so completely that 

 they appear quite small, and that the diminutive eggs of the next 

 spawning period can only be recognized by means of a microscope. 

 These eggs gradually mature till the next spawning period, and the 

 sexual organs finally occupy the largest part of the abdominal cavity. 

 At that time many eggs may be seen in the ovaries which are as large 

 as ripe eggs, but besides these many smaller ones, less transparent, which 

 are still growing. A person not acquainted with these matters would 

 believe that the large eggs are ready for laying, whilst in reality this is 

 not the case. The fishermen know this very well, for only when the eggs 

 are ejected from the sexual opening of the fish at the slightest pressure 

 (compare the preceding treatise by Professor Mobius) are they ready 

 for development, and the fisherman declares that the spawning season 

 has come. 



At this period most of the eggs in the sexual organs are large, lie very 

 loosely in the glands, and come out at the least pressure, often by the 

 mere motion of the fish. From the abdominal cavity they pass outside 

 through the ovarian tubes. This complete maturity of the eggs seems 

 to be very sudden. Some fish with almost mature eggs roam about for 

 weeks without any perceptible change in their ovaria, until on their 



